Reinforced hydraulic hose is well known in industry for use in transporting fluids under pressure, particularly in automotive brake hose applications. These hose assemblies generally comprise a polymeric core hose layer and one or more reinforcing layers formed from strands of fiber or wire material that are braided over the core layer. In most applications, the hose also includes an intermediate hose layer formed over the core hose layer and a first reinforcing layer. A second reinforcing layer is thereafter braided over the intermediate hose layer. Finally, a polymeric cover material is generally formed over the second reinforcing layer to complete the hose assembly.
The reinforcing layers of conventional hydraulic hose assemblies are generally applied by rotary braiding machines such as those described in U.S. Pat. Nos. 4,266,461; 5,099,744; and 5,775,195. Using these rotary braiding machines, strands of fiber or wire reinforcing material are wound upon the hose layers in an interwoven, braided pattern, as known in the art. Generally, the rotary braiding machines are configured to provide a braid pattern wherein the strands are successively passed over and under pairs of oppositely wound strands. This is referred to herein as a 2-over, 2-under braid pattern. In certain applications, it may be desired to further improve hose performance by varying the braid patterns, for example, to optimize burst strength, volumetric expansion, dynamic life, or coupleability of the hoses.
There is thus a need for a hydraulic brake hose which can be formed with reinforcing layers having braid patterns other than the standard 2-over, 2-under braid pattern in both reinforcing layers.